Drying of finely-divided carbonized fuel



carbonized fuel, whetheruartificially fetentsd Nov.

' nniraeisraras warren snoannnrnen, Enwrir' nnsnn,

Lennon, nnennnn, assrenoas To MINERALS snrunarroni nears oonroaarron, ornew roux, n. Y., A oonronarron. 1

AND-,WILIFIAM wanwrcrr srnnmne, on:

pur ne or rrnnnv-nrvrnnn c'hniaomznn F EL.

AMERICAN j NovDrawing. Application filed novemter-ao, 1e22, Serial m5.02,251, and in Great Britain November a 1921. Rcnewed Apri122, 1926.

This invention consists in improvements in or relating to the drying 'offinely divided or naturally carbo'nized, such as coali In our previousUnited States Patent Ap: plication Serial-Nor 4%,106 Wehave .de--

scribed various -process of producing ag-' glon'ierate's from impurecoal, coal dumps and the like adapted for the making of husuchconditions as to facilitate the separation of water therefrom withoutthe production p of briquettesunder water-expelling pressure. lVe havefound that various'agents such ascertain oils, tars andotherhydrocarbons or carbonaceous liquids which are incapable of. formingbriquettes of the carbbnizedmaterials such as coal under the conditionshereinafter described have the properties. (1) of coating the coalparticles, and (2)- of causing the coal particles, when so coated,-'

to flocculate togetlier.-

\Ve have'further found that this flocculat ingefi'ect occurswith verysmall quantities of thelagents referred to when'the coal particles areagitated with the flocculating agent in sufiicient water to makeaflmobile pulp, preferably with aeration. The quan 3 .titiesof thereagents may-be very small,-

stitialspaces a large proportion of water, j but owing to the fact thatthe surfaces of: the particles have become repellent of the H water, itis possible to remove contained water by filtration or draining,preferablyassisted by pressure, and thus the drying of the particlesbecomes a simple matter.- The removal of the water associated w th t thecoated and fiocculated particles maybe assisted by pressure, but it isto be under'--' stoodthat it is not an objectof the present invention toconvert the materials into bri-' quettes, and the coating andflocculating agent does not perform the function binding medium to formbriquettes.

of a.

' The present invention offers particular advantages when the'coalparticles are subs sequently to be made into coke because the .volatilematerials in the flocculating agent are distilled in the coking-oer'at-ion and *rnay thereforebe recovered. re ov'er,"the presence of theflocculating agent assists the coking of special types of coal whichwould otherwise be unsuitablefor making int-0 coke.

The quantity of the fiocculating agent'employedshould be suflicient toproduce the, flocculation at the temperature of-the foilcuit Water. .Itmaybe reduced by using a heated circuit, but preferably thetreatment iscarried out at atmospheric temperature.

From 3- to '5% has been found sufficient when using as agent a-productsuch as anthracene oil, and'coal-tar, coal-tar oil and other re agentsmay 'be employed in like proportion. The following examplesillustratevarious proceedures in accordance with the invention I Example to pass ascreen of 0.4 mm.- aperture. The

ground coal was concentrated by flotation,

using 0.23 kilos." cresol' and 0.06 kilos. kerosene oil per ton ofcoal." The concentrates removed had a water-solid ratio of 1.3 1.

The. concentrates with their j associated water Wereplaced in a vesselof square lrori-' zontal section and. were I agitatedg by an aim pellerrotating with a peripheral velocity ofabout 200 metres per mln'ute.By-pr'oduct coke-oven coal-tar was added during the agitation, thequantity ofltar amounting to 4%, ofthe weight of, thef'dry concentrates.The test was carried out at rootn temperature. The coalbecameintenselyfiocculated and.

readily separablefrom the water. Removal of the bulk ofthe water waseffected by draining; it could be assisted if desired by subjecting'thefiocculated coal to compression. Under a pressureof 310 kilospersquarecmthe' coal became substantially free from vwater, so-muchsothat on drying it I 75 a, Goal froma Durham colliery was ground 5 in awater oven at a temperature of 100 C. for a period of 3 hours, theweightdimin ished by 2.7%,which'indicates the reduction in water content.

, -The coal was 'thus'fe'rmed' into a cake which, however, could 'beeasily-crumbled between the fingers. 7 It will be understood that it isnot essential to compress the coal into cakes in this way although thismay be done both to assistremovalof the water and to facilitate handlingof the treated material.

Example 11. 3

Coalfrom Powell Duffryn collieries was ground to pass a screen with'anaperture of 0.4 mm. :The coal was concentrated by floout at roomtemperature. An intense fiocculation was produced, and when some of thewet. flocculated coal was placed on a screen having 24 apertures perlineal centi-. metre, clear water ran through, and the greater part ofthe contained waterdrained away.

hen thewet flocculated coal was placed in a mould having slit-s foregress of water and subjected to a pressure of kilos. per square cm.,some further water exuded and a cake was formed which contained 12%.

water.

A pressure of 160 kilos. per square cm. produced a cake containing 9% ofwater. Ineither case the cake'crumbled easily in the fingers.

It is possible to eifect not only the flocculation of the coal particlesand the removal of the water therefrom, but also, in the same operation,it is possible toefi'ect the separation of the gangue and otherashf-orming materials from the coal particles. Thus, according to thisinvention, the

finely divided coal particles, mixed with gangue or other ash-formingmaterials, are suspended in sufiicient water to make" a mobile pulp.This pulp is then subjected to agitation (preferably with aeration) witha fio'culating agent of the kind hereinbefore described in quantityinsufiicient to form an amalgam in which the interstitial spaces.

between the particles would be filled with the agent but sufiicient tocoat the coal particles and filocculate them 111 water, the

'netefse'r" gangue particles not being so coated or flocculated, thegangue, with the water, being separated from the coal by draining oriiitration, with or without pressure, but without the productionofbriquettes.

. Y Example III. I I lVaste coal or duff from the 1 Powell Duffryn minein South Wales and contain ing Q3.04% of ash-was made up into a mo .bilepulp with-an'equal weight of water, and

the pulp was agitated with the addition of 4.75%" of by-productcoke-oven coal-tar measured on the weight 'of'the crude coal so as toproduce flocculation. The Wet flocculated coal was then transferred to apress and subjected to a pressure'of 31 0 kilos, per square cm., therebyextruding the water which carried the great proportion of the .gangue,The resulting cake contained only 13% of ash and 5.56%v of moisture.This test was carried out. at normaL atmospheric temperature.

Again the process of flocculating the coal particles may be carried outin such a way that the coal particles are coated and flocculated andseparated in the form of a float supported by bubbles, while the gangueremains in the water. v

Ewampl l V.

The same material as in Example 3, viz, pulverized waste coal or dufffromthe Powell Dufirynmine'in South ales, was. mixed with its own weightof water toform a mobile pulp. 'Therewas added to this pulp thefollowing reagents l.7% by-product coke-oven coal-tar, 0.075% cre'sol,0.075% parafiin oil (these percentages being measuredon the weight ofcrude coal).

After agitation and aeration the flocculated coal, separated as a floatsupported by bubbles and wasremoved and subjected to. a pressure of 310kilos. per square cm. The resulting cake contained only 5.76% of ash and3.87% of moisture.

This test was carried out at normal tom perature.

Having thus described certain 'embodiments of our invention, we claim 1.A process -for,.producing carbonized fuel in finely divided form .whichconsists in agitating a mobile pulp of suitably finely dividedcarbonized fuel with a suitable flocculating agent having thecharacteristics of a frothing agent and. a coating oil under suchconditions that the fuel is flocculated and coated with awater-repellent coating having so little adhesiv'eness as not to causethe fuel to form into briquettes under waterexpelling pressure, andseparating and draining the flocculated fuel.

' 2. A rocess for reducing carbonized fuel in mely divided form whichconsists in. agitating a mobile pulp of suitablyfinely agent and ac-oating'oi'l under such 'co'nditions that the fuel is fioc'cul'altedand coated with a water-repellentboating having so litt l e adhesivenessas not to cause the 'fuel toform into briquettes under water-enp'ellingpressure, and separating and draining thefuel in finely divided formwhich consists in agitating a mobile pulp of suitably finely dividedcarbonized fuelwith=a few percent of. a coal tar under. such'conditionsth'at, the/fuel is flocculated and coated with a" lwaterarepellent 'coa'ting'having so littleadculated fuel. I v

. inchr -hesiveness as not tofcause the fuel'tO "form into briquettesunder water-expell1ng pressure, and separating and draining the floQ- 4.A process for producing. carbonized fuel in finely divided formwhichconsists in agitating acm'obilepulp of suitably finely dividedcarbonized fuel-with'about three percent of a flocculati-ng agent''lin'der such conditions. that the fuel =-is -fiqcculated and coatedwith a w'atenrepellent coatinghaving so, little adhesiveness as not' tocause the fuel to fornilinto briquettes underwater' expelling pressure;and separating the floc Vculatedfuel and s'ubjecting' it to a water;

expelling pressure. a;

l 5. Ayprocess for, producingcarbomzed fuel in finely divide'd formwhich consists in agitating a mobile pulpofsuitably finely dividedcarbonized fuel with a; suitable flocculating agent undersuch conditionsthat the fuel is (fiocciilated and coated: with a water-repellentcoating havingso little .adhesiveness' as not to cause thefuel to forminto briquettes under water expelli 11g pres;

sure, and separating the-.fioceulated fuel and drainingit under apressure-0f the order of magnitude of a :ton per square 'GJA process forproducing1 tabs-tied fuel in nely :d-ivided form W ich' consists inagitating'a mobile pulp of suitably finely:- divided carbonized .fuelwith a few per cent adhesiveness as; not to cause the fuel to formintobriquettes under water-expelling pressure, and separating theflocculated fuel and draining it under 'a p'ressure of the order ofmagnitude of a ton per squareinchJ m-fuel infinely divided formrelatively free bile from ash, which consists inv agitating a 'mbbonized fuel with a suitable fiocculating of a coal. tar under suchconditions ';that the fuel is fiocculated and coatedwith' :a'water-repellent coating. having so little pulp of suitably finelydivided carbriquettes under water-expelling pressure; and separating theflocculated fuel and .ness'as not'to cause the fuel'to 'forin intodraining it under water-expellingpressure,

w y the fuel is dbtained relatively-dr and relativelyfree f J k 8..rocessfor producing carbonized fuel in finely divided form relativelyfree I from ash,v which consists in agitating a mo '3. A ,process forproducing ,carbonlzed repellent coating having so little adhesive-fnessfas not; to cause the fuel to form into. briquettes underwater-expelling pressure, andsepa-rating the flocculated fuel anddraining it 'under water exp'ell'ing pressure, whereby the fuel isobtained relatively-dry and relatively free 'fromash, 3

under such conditions t hat' the'fuel flocculated and coated with awater-repellent coating 'having so little adhesivenesslas not.

to cause 'the fuel to form into briquettes ,unden water e rpellinglpressure, andJseparating the flocculated fuel and drainingit .underwater -expelling pressure, whereby.

-tively free fiomash. c

-10. A process for producingbarbo'nized fuel in fi nely' divided formrlativelyfree the fuel is obtained relativelydry and relay 9. A processfor producing" carbonizedh from ash which consists-insubjectingrsui'tablyfinely divided impure carbonized fuel r to;froth:flotationconcentration with a frothing: agent to produce aconcentrate relatively free from ash, agitating a Inobile pulp of theconcentrate with a few per cent of a'suitableflocculating agent undersuch conditions that the carbonized 'fuel'is"floc culated and coatedwith a water-repellent coating having 501 little adhesivene'ss as -notto: cause the fuel to form into briquettes .arating and drainingthefiOccuIatedfdeL.

from ash which consists subjecting suit- '1l.4 A process for producingcarbonized fuel in finely divided form relatively free under waterezipelling pressure and sepably finely divided impure carbonized fuel to-froth-flotation concentration with a frothing agent including a solubleelement to produce a concentrate, agitating aa inc-'- bile pulp of theconcentrate-with a. suitable -7. A process for producing carbonizedflocculating agent. under such "conditions that thecarbonized fuel isflocculated and and draining the flo'cculatecl fuel.

12; A process for producing carbonized water-expelling pressure, andseparating}- Ill) with a waterrepellent coating having solit-tleadhesiveness as not to cause the fuel to form into briquettes underwater-expeh' ling pressure, and separating and draining the fioccnlatedfuel.

13. A; process for producing carbonized fuel in finely divided formrelatively free from ash which consists in subjecting suit-- ably finelydivided impure carbonized fuel to froth-flotation concentration with afrothing agent containing a few per cent of a coal tar and an oilysubstance under such conditions that the carbonized fuel is flocculatedand coated with a waterrepellent coating having so little adhesivenessas notto cause the fuel to form into briquettes under water-expellingpressure, and separatingand draining the fiocculated fuel.

14. A process for. producingcarbonized fuel in finely divided formrelatively free from ash which consists in subjecting snitably finelydivided impure carbonized fuel to froth-flotation concentration with afrothing agent under such conditions that the carbonized fuel isflocculated and'coated with .a water-repellent coating having so littleconditions that the carbonized fuel is flocculated and coated with awater-repellent coating having so little adhesiveness as not to causethe fuel to form into briquettes under water-expelling pressure, andseparating the fiocculated fuel and draining it under Water 'tofroth-flotation concentration with a few per cent of a coal tar undersuch conditions 'that the carbonized fuel is .flocculated and coatedwith a water-repellent coating hav.--

ing-so little adhesiveness as not to cause the fuel to form. intobriquettes under water-expelling pressure, and separating theflocculated fuel and draining it'under water-expelling pressure. v 17. Aprocess for producing carbonized fuel in finely divided form relativelyfree fuel in finely divided form relatively free from ash which consistsin'subjecting suitably finely divided impure carbonized fuel tofroth-flotation concentration with a frothing agent containing a few percent of a coal tar product under such conditions that the carbonizedfuel is flocculated and coated with a water-repellent coating havingsolittle 'adhesiveness as not to cause the fuel toform into briquettesunder watere'xpelling pressure, and separating the flocculatcd fuel anddraining it under a pressure of the order of magnitude of a ton persquare inch.

In testimony whereof we have signed our names to this specification.

\VALTER BROADBRIDGE.

EDWIN EDSER.

WILLIAM WARWICK STEN NIN G. I

